- && threadID != tsp->master
- && !Threads[tsp->master].is_searching)
- Threads[tsp->master].wake_up();
- }
-
- // If this thread is the master of a split point and all slaves have
- // finished their work at this split point, return from the idle loop.
- if (sp && Threads.split_point_finished(sp))
- {
- // Because sp->is_slave[] is reset under lock protection,
- // be sure sp->lock has been released before to return.
- lock_grab(&(sp->lock));
- lock_release(&(sp->lock));
- return;
+ && this != sp->master
+ && !sp->master->is_searching)
+ sp->master->wake_up();
+
+ // After releasing the lock we cannot access anymore any SplitPoint
+ // related data in a safe way becuase it could have been released under
+ // our feet by the sp master. Also accessing other Thread objects is
+ // unsafe because if we are exiting there is a chance are already freed.
+ lock_release(sp->lock);
+
+ // Try to reparent to another split point. Only for slave threads
+ // that are not master of any active split point.
+ if ( !sp_master
+ && !is_searching
+ && !do_sleep
+ && !do_exit
+ && !splitPointsCnt
+ && Threads.size() > 2)
+ {
+ for (int i = 0; i < Threads.size(); i++)
+ {
+ SplitPoint* oldest = &Threads[i].splitPoints[0];
+
+ // Find the first oldest split point with still all slaves running
+ if ( Threads[i].splitPointsCnt
+ && oldest->slavesMask == oldest->allSlavesMask
+ && !single_bit(oldest->allSlavesMask))
+ {
+ lock_grab(oldest->lock);
+ lock_grab(Threads.splitLock); // Needed by is_searching
+
+ // Retest all under lock protection, we are in the middle
+ // of a race storm !
+ if ( !is_searching
+ && !do_sleep
+ && !do_exit
+ && Threads[i].splitPointsCnt
+ && oldest->slavesMask == oldest->allSlavesMask
+ && !single_bit(oldest->allSlavesMask))
+ {
+ oldest->slavesMask |= 1ULL << idx; // allSlavesMask is not updated
+ curSplitPoint = oldest;
+ is_searching = true;
+ }
+
+ lock_release(Threads.splitLock);
+ lock_release(oldest->lock);
+
+ break; // Exit anyhow, only one try (enough in 99% of cases)
+ }
+ }
+ }